Dynamo-electric machine.



C. RF. AHLM. DYNAMO ELECTRIC MACHINE. APPLICATION FILED JAN. 2s. 1.911.

Patented sept. 30,1913.

3 SHEETS-SHEET 1.

l 70 NYM C. E. P. AHLM.. DYNAMO ELECTRIC MACHINE. APPLICATION FILED11111.23, 1911.

Patented Sept. 30, 1913.

3 SHEETS-SHEET 2.

.0. E. F. AHLM. DYNAMO ELECTRIC MACHINE.

APPLICATION FILED JAN. 23, 1911.

Patented Sept. 30, 1913.

i 3 SHEETS-SHEETS.

o f 4' 4M f N if i alam Y CHARLES: E. F, AHLMfor c'LEyELaND, OHIO.

DYNAMo-ELEc'r-Rio MACHINE.

,T a'ZZ cham t may-Lconcem.' j l Be it known'that I, CHARLES E. AHUM, a'citizen of the United States, lresiding at Cleveland Vin the 'county of'Cuyahoga and` State'of- 1hie,` haya inventedl azcertain new andusci-ful Improvement in-'Dynamb-ElectricMachin'es, ef which thefollowing is ,a full, clear, and exact description, reference 4 beinghad' to thezaccompa'nyin drawings,

My applicationJN0. 543,7 6, .filed February 3.4; 11910 (of-'whioh-thisis a division) showsfandfdesoribes aldynamo electric machine-operatingwithl afconsta-nt potential' fori'arying speedsv-al'machineas a genera.--tor'giviiig a current of--Sconste'int otential for varying speeds,though receivingcurrent 'of constant potential. A characteris-r tic-ofthe machine is that there is a single armature under the linfluence oftwo magnet lields, onelof which is constantand'the other of i whichAincreases -in-"sti'engtli with the speed.'l The windings, circuits andconneci' tions byiwhich this .isi accomplishedor, what maybe called'vthe electric features of Ithe machine are claimed in the parent application referred to. 1

" The presentvv application relates to the mechaiiicalfeatures by `whichvsuch dynamo electric machine may be constructed as van,I

elicient pieceof mechanism.

'lhedrawing-s showa dynamo electric inachiiie ofthe two jpole typeembodying this invention,

i `Figure l `isa vertical-longitudinal section through the machine; Fig.Q, is a transverse vertical section of the same; Fig. is Va horizontal'longitudinal section, omitting the f armature with itsshaft and`comiinitator and bearings; Fig. 4 is a vertical transverse sectionthrough the machine adj'ac-ent to the cominut'atoi' brushes; Fig. 5 isan end -view on a reduced scale Fig.- 6 is a diagram illustrating theelectromagnetic operation.

The mainframe of tlierinachine, desigu :cated 40, consist-s of a hollow,barrel-like,

iron casting extending above and below the armature and forming also aportion of the ends ofthe inachineythese end -portio-ns'be ing annular,as shown! at 41' Aand 42. The` annu-lar portion 42de connected with-themain portion 40by a sleeve-like'portion 43 nearer'- the axisand anoutwardly extending' annular portion 4. Centrally mounted on the endvportions 441;,fiifid 42 arediskelike members@ and 46,-preferab1y ofsomenon- Specicaton of Lettinrsflatent.

Original-application led February 14,191.0, Serial No. 54353326. Iviiedand this 23, 1911. Serial No.' 604,120.

y balls (S2, and an outer ring coies, becker fields, the

-magnetsy ythe ironie lilbutyinfthei embodiment shown,

Patenten sepeeo, 1913- opplieation filed January magnetic niateriah'asbrass or aluminum, and shown as removably secured byscrews 52. In theseend disks 45 and 46, is mounted the armature shaft insuitableballbearings, as shown.' The 47, the mounting being frame openingsfwhich thedisks occupy 'are large enough so that the removal of either disk allowsthe armature to be drawn out' of that end of the machine. The casting 40may be flattened on its outside, above and .below the armature, asshown, thereby providing suitable bases on either of which the frame maystand. Figs. 1 and 2- omit the armature winding but show the shaft 47and the core 48, which maybe allan'iinated strii,oA

ture of disks, or otherwise constructed, as'

desired. It is shown as composed of mem-` bers surroundinfr the shaftand-held lin-place shaft, The wintlingsvas will be understood, occupynotches 5l in the core.

, 53 designates the comnriutatorbars'insu-A latingly carried by a`commutator core 54 on th'e shaft and locked in'place by a nut ,screwingon to that core 'against a collar 5.6 thereon. Beyond the commutatorcore on one end and beyond 'the flange 50 on the other, are suitabledistancesleeifes 58 and '59 ball bearings reand 'beyond these are thevferr-ed to." The ball "bearing, .in the -forin shown, consists of a ring(30 surrounding the shaft and abutting the distance. sleeve, G3seated-iii ,the disk member 45 and 4.6,.there being a dis- Atance sleeveGlontlie shaft for holding the ring 60viii place. A suitable dust-capis-provided by the disk G5 threaded in place and.

vby suitable flanged fittings 49 and 50 on the held by a pin 67":iswillbe well understood.. I

64 indicates ya cap-plate atthe cominiitator end ofthe shaft., the otherend beingV connected witligthe driving or driven mechanism, not shown.

Carried bythe main body portion 40 of the frame are two magnet cores 70which have the usual pole faces 71 and suitable windingsfQ,illustratedby dotted lines in Fins. l and 2. These ma'net cores 70 areshown as held in place by screws 73. These with their windings,.constitute operationtof which will be hereinafter'.described. Theframe'40' constitu-tes a ring over the' ends of armature magneticallyconnecting the poles 70. The Aofsthe main field are supported bycross-section so are out of any substantial magnetic con-' nectiontherewith. rihe cores of these magnets are designated 75. They haveflared pole faces 76 and. lare 'connected at their outer ends to theiron connecting bar Z 7 by screws 78. `This connecting bar Z7 is shownas carried byl screw bolts .794 on a cap-plate 80 which 'may ,bev madeet aluminum' or other nonmagnetic material. It desired, the cap-platemay be made separately and the connecting bai` 77 secured to the mainframe, either through interposed non-mag netic material or material ofsmal-l enough that the magnetic flux will not be suicientto intert'erewith the opera tion. y

Outside of the reduced portion 43 I mount the support for the commutatorbrushes, consisting of brackets 85 supported on suitable insulation. 86and carrying pivot pins 7 on which are mounted arms 88 carrying the twopairs ot'brushes, designated S20, Q1, and 23, 24. Coiled springs 89surrounding the pivotlpins 87 tend to keep the brushes on thecommutator. rlhe brushes projecting freely through openings 84 in thetraine portion 43. The brushes are covered by a removable sleeve-likecover plate 90 resting on the main frame and secured to the :traineportion 42 by screws 91. This makes a vvery simple construction and oneallowing easy access to the brushes. For lthe sake of completeness, Iwill now describe the electromagnetic operation of the machine, asillustrated more particularly in the diagram of F ig. (3. In thisdiagram the windings J and F are main-field windings corresponding tothe winding 82 of Fig. 2, while the double bucker field windings L, Hand M D on the poles 70 correspond to the winding 72 of Fig. l. Thearmature illustrated is i wound as for an ordinary two-pole machine,

tilt

being connected to successive commutator bars, on the closed circuitprinciple, as is well understood. The t'wo poles 70 are, of course, ofopposite polarity and the horseshoes T5 are so placed that thoseof theirpoles which are adjacent to the poles have a polarity opposite theretorespectively. Thus, asshown in the drawings, the upper pole 70, forexample, inthe operation of the machine, is a north pole; the upper poleof the right hand horse-shoe Z5 a south pole, and so 0in-this polaritybeing indicated by the designating letters N and S on the diagram. 20and 2l indicate twocoininutator brushes related to themain field, and 23and 2e indicate commutator brushes related to the bucker iield. Theshunt winding of the main field, shown, is in series with a small coil,indicated byD and H, constituting a portion of the bucker iield andacting as a teaser therefor, the principal bucker ltield windings beingindependent of the main tield windings, as hereinafter described.

. Starting from the .mutator brush 21, the main ladal'ited, whenattracted, to

:terasse Referring to the circuits shown i' ft. the letters 1A and Bindicate the Aii y lead A, or from the come field wind' and the teaserwinding may be tracer" followss-vizt the line C to a fst/*turn (teasercoil) around the core 79, n n the line E to a winding F (main tieid) 'onthe cores 75, thence via the line Gto thel teasercoil H on the othercore T0, thence 7i 'via the line l to the main ieid-winding el,

thence via the line l to the brush 20. it willbe observed that therelative directiono the main coils and teaser' coils .is such that ir acurrent be flowing to give the main poles the polarity designated, the.teasen coils will give the bucker poles a polarity? opposite to theadjacentmain poles, as also" designated. The winding of the main porytion of the bucker ield starts from the brush. 35 23 through the coil Lto the line@ and' through the coil' M to the brush 24, and-I, thesecoils are of high resistance, and are wound in the same direction as theteaser coils. The lines ot torce ot the two .fields are illustrated bythe conventional broken lines with arrow heads thereon.

As shown in Fig. 6, T represents a batg tery in a shunt across the mainleads A and B. U represents an automatic switch adaptg5 ed to controlthe main line and having a compound winding; one winding of this switchbeing in a shu-nt V across the leads A and B, and the other winding W'in series in one of the'leads, as the lead A. Y in dicates an armatureunder the influence ot this compound winding W and X` which is close thebreak in the lead A between the switch'and hat tery.

Let us assume that the machine is a. generator and that the armature isconnected with an axle ofthe car, for example, andv that the switch iswound to pick up its armature when a certain' current. is generated, saythat resulting from a train speed of fifteen miles per hour. Now, as thetrain starts, the armatures rotate slowly and the main line is open atthe switch .Y so that the voltage builds up in the shunt V through tilethe winding U of the switch. Duringthis j period, before the switchpicks up, the main field and the bucker eld (due to the direction givenby the teaser) are operating to give currents of such direction as tocause iae the successive poles to have opposite signs. The actualdirection of this current depends on the residual magnetism, but theirrelan tive direction is thus fixed. The bucker i'ield current (due tothe high resistance oit-its 1% winding) is so small in the earlystage'o'i rotation as to be negligible. As soon, however, as the switchpicks up its armature, thereby throwing the battery on to the line,

the counter-electroznotive torce of the batist# 50 y lies, said framebeing open on the sides of tery establishes a definite direction for thecurrent suitable to 'the battery, and this current acting ,on theWinding of the main field and the teaser windings of the bucker'ieldwhile it may reservetheir original polarities (if necessary) willcontinue their relative polarities. ow, as the speed increases,

the main field voltage rises proportional' to.

the speed, inasmuch-as this iield has a constant excitation, initially,at least, due to the battery, while the voltageof the local bucker fieldalso rises proportional to the speed, be-

ing connected solely in series with the arma ture andthus having anexcitation varying with the speed (the constant excitation b theteaserbeing negligible), and as the e fects of these two fields areopposite, the main line current, given out by the machine, is thedifference bet-Ween the main field voltage and the bucker field voltage,which is a constant irrespective of the speed. With the generator,connected as described, when lthe battery has been full vcharged, the

-tator brushes, and the removable caps over such holders all contributeto the etiiciency` .of the machine. p in this'application. Whenassociated with the windings and circuits .claimed in my parentapplication referred to, a simple and eiective constant potentialgenerator or motor is provided.

Having thus described my invention, what I clairn'is y p l. In a dynamoelectric machine, the combination,w1th an armature, of a frame forming amagnetic ring in planes parallel with the plane in whichvthe axis of thearmature the armature, pole pieces carried by such main longitudinalring, additional pole pieces at the open sides with a differentinagnetic circuit from the pole pieces first mentioned, and means forsupporting the additional pole pieces.

2. In a dynamo electric machine, the coinbination, with an armature andfield magnets, cfa magnetic ring connecting the lfield lmagnets andcarrying the magnetic flux through the frame of the machinelongitudinally of the armature and having sidel openings, at least oneof the ends of the frame having an opening sufficient for the Thesefeatures are covered removal of the armature, a bearing carried by suchendv at such end opening, independent'magnets at the sides, and meansvcarried by the magnetic ring for supporting., such` magnets at thesides. l

3. The combination of a barrel-like fram formed with open sides and endswith central openings in them, an armature mounted Within said? barreland having its shaft occupying said openings, removable end membersinwhich the v"armature shaft is journaled and which are mounted ontlie'frame at said openings, pole pieces carried by said frame,additional pole pieces at the open sides and independent of the fullinfluence of magnetic luX throughthe barrel-like frame, and meansforsu'pporting the additional pole pieces.

4. The combination of a barrel-like framev formed with open sides, anarmature Vmountedaxially within said frame, removable end members inwhich I the armature shaft is journaled, pole pieces carried by 'saidframe,

other pole pieces carried at such open sides,-

and means for supporting the last mentioned pole pieces and removablyvclosing the sides.

5. In a dynamo electric machine,the combination of a main frame, ashaftjournaled therein, an armature on the shaft, pole pieces carried bythe frame coperating with the armaturesaid pole pieces being magneti#vcally connected through the end portions of the frame, a plurality ofpairs of additional pole pieces, each pair having a connecting bar ofmagneticmaterial independent the magnetic members carryingsaidadditional pole pieces and forming caps for the sides of the frame. i

6. The combination, with an armature, of pole pieces, a frame for themachine extending beyond theends of the armature and supporting thearmature shaft, said frame carrying the magnetic flux ofthe pole piecesmentioned, additional pole pieces coperatingwiththe armature, andremovable side i main magnetic flux of said frame, and nonmemberscarrying such. additional pole pieces and `mounted on the frame.

7. In a dynamo electric machine, the combination, with an armature,its.shaft and commutator, of an integral frame adapted to contain thearmature and commutatorv and having' annular` end portions beyond thearmature and commutator ends, a pair of central end members .carried'bythe' frame, the shaft for the armature bein journaled in said endmembers, the frame ge duced diameter around the commutator,

brush Aholders comprising bracket's'mounted on the outer sides of suchieducd portion and arms pivoted to the brackets, there 'being openingsthrou h Vthe reduced portion through which brus ies carried by the saidarms ot the holders'are adapted to extend into Contact with thecommutator, and pole ing of ref pieces cam'ed by said imm@ smit havingtheir nmgnetc -m carried by Said angular end portions of the frame.

8. in. a, dynamo electric machine, the cornbuaton, with an aamzatlafre,of L Emme therefor carrying poe pieces, an amnut'ure slaaf@ acommunimcyA chereon, said frame appmoaehmg the shaft adjacent wh@commutator and being Subsaniall'y cylindrical :md o xreduced diametev@about the commutatm and' Hanging outwmdflly am thel Guten end; thereduced. pc 1'1,f n,. brush1 hoder's meunted en the outer face of suchreduced pmrtom of the frame, chere being @pen-ings @Hough the reducedpomten throng-i111 Whnh 15 baushes camfed by the, holders are wcmped.-

te: extend im@ cmntact with the commumtrg and? w sleeve-like cap forsaid bueh Mobiele?,- i'emefmbly securec t@ fname in engage meurt VWLM;che boc'y thereoi acdi Wiu szch euml-madly flanged peten. A

En estmongr wl'leeo, hereunto ax my sgmaiume in the presence of twovviinflesses;

CHARLES E. 1f; Amm'.

